You make it sound as if indulgences is in the Bible. It is not. It was first invented by Pope Urban II around 1099 to encourage people to fight in the Crusades. As all false doctrine, it reached the pinnacle of corruption when Pope Leo needed funds to pay for the Vatican.
What you neglect in your theology is that ANY fruit that we bring forth (part 3), is solely because of the work of Christ in us. He is the vine. We are the branches. Without Him we can do nothing. There IS no good work that we can do apart from Christ. Indulgences is a heretical doctrine and takes away from the work of Christ and the working of the Holy Spirit.
The idea is there in embryo, without being fully defined, much like the doctrine of the Trinity, the Eschaton, and even the clear-cut Table of Contents of the Canonical collection of the Bible itself.
As for purgatory, I said, not that it is explicitly named, proved, and fully defined, but that it is consistent with what the Bible teaches about three things:
This requiting, refining, and effective spiritual sharing is all about how He deals --- not with the lost souls, the damned--- but with His children -- according to Scripture. In God's great mercy, I hope that's every one of us.
The doctrine WAS handled corruptly at the time (11th century). It was simony, "money for spiritual good," always known as a sin. You won't find any Catholic today that denies that simony is wrong, neither Tetzel nor the simoniacal popes were saints, and (on the topic of simony) Luther was certainly right.
What we affirm in our theology is that ANY fruit that we bring forth, is solely because of the work of Christ in us. He is the vine. We are the branches. Without Him we can do nothing. There IS no good work that we can do apart from Christ.
Correctly understood, "Indulgences" is not a heretical doctrine because it does not take away from the work of Christ and the working of the Holy Spirit. On the contrary, it shows how God has graciously accomplished it all in His Mystical Body, in which we are joined to Him and members of one another.